Refrigerator evaporator and method of making same



Nov. 22, 1938. c. STEENSTRUP 2,137,861

REFRIGERATOR EVAPORATOR AND METHOD OF MAKING SAME Filed Aug. 28, 1929 FL J.

IhVenton ChhLstLcm fite'enstr'uqa id LZm/ HLs After-n95 Patented Nov. 22, 1938 u 2 137 351.

UNITED STATES PATENT OFFICE REFRIGERATOR EVAPORATOR AND METHOD OF MAKING SAME Christian Steenstrup, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application August 28, 1929, Serial No. 389,050 20 Claims. (Cl.62--126 My invention relates to refrigerator evapopassages I9 extending throughout the continuous I rators or expansion chambers and the method wall and Opening at both ends thereof .into the of making them and has for its object the proheader I thereby providing a sharp freezing vision of .an improved evaporator construction of chamber completely surrounded by the wall. By 5 simple form which canbe readily fabricated this arrangement refrigerant from the header 5 from metal plates. This evaporator includes a 4 can freely circulate through the passages I9 header and a continuous curved wall having the which communicate therewith so as to freeze edges thereof integral with the header and pro articles placed on the shelf l6 and absorb suflivided with a plurality of passages for the circulacient heat from the interior of the refrigerator 10 tion of refrigerant therethrough from the header, cabinet, or the like, in which the evaporator is 10 a portion of the curved wall depending from the placed, to maintain the same at the desired low header constituting a shelf for receiving and suptemperature. I prefer to form or fabricate the porting articles such as receptacles containing continuous wall l5 of a one-piece corrugated or fluids to be frozen, and the entire evaporator embossed plate 2|] and a one-piece flat plate 2| being adapted to cool a refrigerator cabinet Or which is folded over the edge of the corrugated 16 the like; In accordance with my improved methplate and secured thereto as indicated at 22. 0d of making this evaporator I join together two The wall portions of the two plates cooperate plates or sheet metal walls, one of which is corso that the corrugations of the plate 20 ,form a rugated, and form them to constitute a shelf with series of separate parallel passages l9 in the wall 20 the edges of the plates extending upwardly, and I5. These plates constitute inner and outer shells 20 utilize the edges of the plates to form a header of the evaporat Liquid refrigerant is pp from which refrigerant can circulate between to the header of the evaporator by the supply the plates, so as to freeze articles placed on the p p 3 and vaporized refrigerant is Withdrawn shelf and provide the evaporator with the retherefrom through P p 24 which is turned 25 quired heat absorbing surface. upwardly at 25 in the header and is provided with 25 My invention will be more fully set forth in the a baffle plate 5 which P s q d re ri erfollowing description referring to the accomant from being withdrawn from the header, it panying drawing, and the features of novelty being understood that the level of the refrigerwhich characterize my invention will be pointed ant in the header 0 s s y below t e baffle out with particularity in the claims annexed to In accordance withmy improved method f 30 and forming a part of this specification. making the above described evaporator construc- In the drawing, Fig. 1 15a perspective view of tion, I form the corrugated plate 20 with upan evaporator embodying my invention, partly turned portions 21 and embossed arcuate ends broken away; Figs. 2 to 5 inclusive show the or header portions 28, and the flat plate 2| with evaporator in several stages of its manufacture upturned portions 29 adapted to conform to the 35 when it is made in accordance with my 1111- upturned portions of the plate 20 and arcuate proved method, and Fig. 6 is a. front elevation ends or header portions 30 embossed oppositely 'of a refrigerator having my improved evaporator to the end portions 28 of the plate 20, the edges therein. of the plate 2| being turned downwardly as in- 40 Referring to the drawing, the evaporator condicated at 3|. I then place or superpose the 40 struction which I have shown as illustrative of plate 2| on the plate 20 so that the complemenone manner of carrying out my invention, intary header portions register and fold the edges cludes a cylindrical header Hi, the ends of which 3| thereof Over the edges of the plate 20 and bend are closed by caps II and I2, the caps being the plates thus joined together approximately provided with lugs l3 and II for supporting the into the form shown in Fig. 4. 45 evaporator in the refrigerator cabinet, as shown In order to prevent the plates 2|] and 2| of the in Fig. 6. These lugs are made hollow and of evaporator being spread apart by the pressure of small cross section to reduce the heat leakage the refrigerant therein, I prefer to securely braze from the box topto the evaporator. A 0011- the plates together and in order to do this most tinuous wall I5 is formed with a flattened poreffectively it is desirable to bring the plates into 50 I tionu l6, and upwardly curved ends II which are as close mechanical contact as possible. I do integral with the header In as indicated at I8 and this by pot W ldin h pl 0 and e h r constitute laterally and downwardly depending between the corrugations Where the corrugations side walls for supporting the shelf from the terminate near the opposite edges of the sheet 20 header. This wall is provided with a plurality of as indicated at 32 in Fig. 3 when the plates are in the form shown in Fig. 4, and while the plates are in this form I place copper wires 33 in each of the passages formed between the corrugations of the plate 20 and the plate 2| of such length as to extend entirely through the passages. After the plates are spot welded together in the form shown in Fig. 4 I bend them into the form shown in Fig. 5 and weld the arcuate portions 28 and 30 of the plates together where they come in contact at 34 to form the cylindrical header III; each of the sheets or shells 20 and 2| thus has its ends welded together in-a single seam extending along the vertical median plane of the assembled evaporator. It will be noted that when the shells 20 and 2| are welded together at points such as those indicated at 32 in Fig. 3, there is a substantial distance between the welded portions of the plates. When the plates are bent, there is a tendency for the inner plate to be compressed and the outer plate to be stretched, and it is evident, therefore, that the bending of the plates will stretch the outer plate over the inner plate and securely bind them together without the necessity of providing welded connections over their entire area. This binding action produced during bending thus provides the close mechanical contact desired for the brazing operation. I then press the caps H and I2 in the ends of the header"), weld them thereto, and place the evaporator in a suitable brazing furnace so as to melt the copper wires 33 and securely braze the plates 20 and 2| together and the caps II and [2 in the cylindrical header thereby completely uniting the sheets and sealing all the edges thereof. By brazing the plates 20 and 2| together in this manner the portions of the corrugations formed in the plate 20 in contact with the plate 2| are brazed thereto throughout their length and closely adjacent the wall of the header l0 so that the evaporator will effectively withstand high pressure without any bulging of the walls. As the header I0 is cylindrical, the sheet metal used in constructing the evaporator can be made quite thin as this form of header provides for the most economical use of sheet metal to withstand the desired pressure and, as the portions of the corrugations in the plate 20 are brazed or united to the plate 2|, the sheet metal is also utilized to the best advantage to withstand pressure so that high pressure in the evaporator will not cause any separation of the plates 20 and 2|. By this arrangement the entire evaporator construction can be made of thinner metal than the constructions heretofore proposed so that a substantial economy in the manufacture of the evaporator is attained. The

evaporator may then be finished in any manner desired, but I prefer to coat the same with a suitable vitreous enamel.

Modifications of the construction which I have disclosed and the particular method described will occur to those skilled in the art so that I desire my invention not to be limited to the particular construction shown, or the particular method set forth, and I desire in the appended claims to cover all modifications which do not depart from the spirit and scope of my invention.

WhatI claim as new and desire to secure by Letters Patent of the United States is:

1. An evaporator for refrigerating machines including two curved plates secured together to form a passage for the flow of refrigerant betweenthem, the opposite ends of both of said plates being formed and secured together to constitute a header.

2. An evaporator i'or refrigerating machines including a curved corrugated plate and another curved plate secured thereto to form passages for the flow of refrigerant between said plates, the opposite ends of both of said plates being formed and secured together at the ends of said corrugations to constitute a header.

3. The method of making an evaporator for refrigerating machines which includes forming semi-cylindrical portions at the opposite ends of smooth and corrugated plates, joining said plates together to form passages for the circulation of refrigerant between them, and joining the opposite ends of said semi-cylindrical portions together to form a header for the evaporator.

4. The method of making an evaporator for refrigerating machines which includes attaching the end of a corrugated plate and another plate together, and pressing said plates together by bending said plates to the form required in the completed evaporator.

5. The method of making an evaporator for refrigerating machines which includes forming the opposite ends of a corrugated plate and another plate so that they can be joined together to form a header, attaching said plates to each other adjacent the ends thereof to form passages between them, bending said plates to the form required in the completed evaporator, and joining the opposite ends of said plates together to form a header.

6. The method of making an evaporator for refrigerating machines which includes forming the ends of a corrugated plate and another plate so that they can be joined together to form a header, attaching said plates to each other adjacent the ends thereof to form passages between them, bending said plates to the approximate form required in the completed evaporator, joining the ends of said plates together to form a header, and uniting the ridges of said corrugations with said other plate.

'7. A sheet metal evaporator comprising an outer one-piece shell having an arcuate portion and laterally extending side walls bent to form a sharp freezing chamber or chambers, an inner one-piece shell having an oppositely formed arcuate portion, and laterally extending walls cooperating with the side walls of the outer shell, said two arcuate portions registering complementally to form a substantially cylindrical header, one of said laterally extending walls being embossed to provide passageways leading from said header.

8. A sheet metal evaporator comprising an outer one-piece shell having an arcuate portion and side walls extending outwardly and downwardly, said side walls being bent to form a sharp freezing chamber or chambers, an inner one-piece shell having an oppositely formed arcuate depression, and outwardly and downwardly extending side walls cooperating with the side walls of the outer shell, said two arcuate portions registering complementally to form a substantially cylindrical header and said cooperating walls providing means for the passage of refrigerant from said header, said two 'shells being secured together by welding, each of said shells having a single welded seam extending longitudinally along the vertical median plane of the assembled evaporator.

9. A sheet metal evaporator comprising outer and inner shells fabricated to each form a portion of a cylindrical header and laterally and downwardly depending sidewalls, one of said side walls being. corrugate d, -'said shells being welded together in the'spaces between the corrugations before bending, said. welded side walls being bent to form the sides and bottom of a sharp freezing chambers V r 10. A process of making an evaporator for a refrigerator from two sheets of metal, which comprises forming complementary header depressions in a portion of each sheet and laterally extending parallel corrugations in one sheet opening at one tending parallel corrugations in one sheet, said corrugations opening at one end into said header portion and terminating near the opposite edge' of said sheet, superimposing said sheets so that .the' header portions register, welding the sheets together between the corrugations, and thenbending the sheets thus secured together into the formlof an evaporator, the sheets being sealed by uniting the edges thereof.

12. A process of making an evaporatorfor a frefrigerator from two sheets of metal, which consists in forming complementary header depressions in each sheet and laterally extending parallel corrugations in one sheet, said. corrugations opening at one end into said header portion and terminating nearthe opposite edge of said sheet, superimposing said sheets so that the header portions register, welding the sheets together betweenthe corrugations and then bending the sheets thussecured together into the form of i an evaporator. 13; A sheet metal evaporator comprising an outer one-piece shell having an arcuate portion and-:side walls extending outwardly and downwardl'y,said side walls being bent to form a sharp freezing chamber or chambers, an inner onepiece shell'having an oppositely formed arcuate depression, and outwardly and downwardly extending side walls cooperating with the side walls of the outer shell, said two arcuate portions registering complementally to form a substantially cylindrical header and said cooperating walls 5 providing means for the passage of refrigerant together.

from said header, said two shells being secured 14. A sheet metal evaporator comprising an outer one-piece shell having an arcuate portion and side walls extending outwardly and downwardly, said side walls being bent to form a sharp freezing chamber or chambers, an inner onepiece shell having an oppositely formed arcuate depression, and outwardly and downwardly extending side walls cooperating with the side walls of the outer shell, said two arcuate portions registering complementall'y to form a substantially cylindrical header and said cooperating walls providing means for the passage of'refrigerant from said header, said two shells being secured together by welding.

15. A sheet metal evaporator comprising. an outer one-piece shell having an arcuate portion and side walls extending outwardly and downwardly, said side walls being bent to form a sharp freezing chamber, an inner one-piece shell having an oppositely formed arcuate portion, outwardly and downwardly extending side walls cooperating with the side walls of the outer shell, said two arcuate portions registering complementally to form a substantially cylindrical header, one of said laterally extending side walls being embossed to provide passageways extending from one side to the other of said header, the embossed portions of one of said walls in contact with the other wall being united therewith closely adjacent the wall of said header.

16. The method of manufacturing an expansion chamber for a mechanical refrigerating machine, comprising, first corrugating one of two walls, then welding the two walls together between the corrugations and at or near their peripheries, and then bending the integral construction to form a plurality of walls of a sharp freezing chamber adapted to receive a receptacle.

17. The method of manufacturing an expansion chamber for a refrigerating machine, comprising, flrst corrugating one of two walls, then welding the two walls together between the corrugations, and then bending theintegral construction to form a plurality of walls of a sharp freezing chamberadapted to receive a receptacle.

18. The method of manufacturing an expansion chamber for a refrigerating machine comprising, flrst embossing at least one of two walls to provide portions of a header and a plurality 20f, passages communicating therewith, then welding the two walls together between the embossed portions thereof, then bending the integral construction until portions thereof come into contact toiform walls completely surrounding a freezing chamber, and securing together the walls of said freezingchamber along their line of contact.

19. The method of manufacturing an expansion chamber for a refrigerating machine which comprises providing two sheet metal walls, embossing at least one of the walls to provide a header portion, corrugating at least one of the walls to provide passages adapted to communicate with said header portion, then welding the walls together between the corrugations, and then bending the integral construction to form a plurality of walls of a sharp freezing chamber. 20. A sheet metal evaporator comprising an outer one-piece shell having an arcuate portion and side walls extending outwardly and downwardly, said side walls being bent to form a sharp freezing chamber, an inner one-piece shell having an oppositely formed arcuate portion, outwardly and downwardly extending side walls cooperating with the side walls of the outer shell, said two arcuate portions registering complementally to form a substantially cylindrical header, one of said side walls being embossed to provide passageways extending from said header, the embossed portions of one of said walls in contact withthe other wall being united therewith closely adiacent the wall of said header.

CHRISTIAN BI'EENS'I'RUP. 

